Improvement in adjustable seats



B. N. 'HEMENWAY.

improvement in Adjustable Seats` No. 129,560, Patentedlu|y16,v1872.

' grooves, or slots.

UNITED STATES PATENT OFFICE.

BICKFORD N. HEMENVAY, OF ROOKLAND, MAINE, ASSIGNOR OF ONE-HALF OF HIS RIGHT TO WARREN C. PERRIGO, OF SAME PLACE.

IMPROVEMENT IN ADJUSTABLE SEATS.

Specification forming part of Letters Patent No. 129,560, dated July 16, 1872.

Description. Figure lis an elevation of the whole device.

Fig. 2 is a sectional view of the shaft on thel line .fr 4v, Fig. l. Fig. 3 is a side view of the pin D.

A is the seat. B is the shaft or upper standard. O, Fig. l, is the lower standard or bottom part of said seat, stool, or chair, and is a tube to receive the shaft B. D D, Fig. 3, is

the peg or bolt passing through tube C, in

which the shaft B plays up and down. This shaft, as seen in Fig. l, is indented' at any desired intervals with semieircular cavities, O ne side of peg or bolt D, Fig. 3, is hollowed out to allow the shaft B B to pass easily up and down tube G. The other side of said peg or bolt is semicircular, to lit the cavities in shaft and hold the seat firmly at the given height.

When the semieircular side of bolt D D is in its corresponding cavity in shaft, by turning said bolt or peg one-half round the concave side of bolt or peg is brought next to the eavity and the shaft may be raised. When the shaftisraised as required, by then turning said bolt or peg one-half round the convex side is brought into its cavity and then the seat is firmly stayed, and the pressure of the seat, forcing shaft down, wedges the same and makes said seat as firm as can be desired.

The tube C, Fig. l, has a slight groove at one side, as seen at L, passing up and down its whole height, in which a small peg, pin, or bolt, as seen at lower part of shaft, Fig. l, fits, to keep the 'tube from turning and thus disarranging the working of concave and convex sides of bolt or peg D D with the cavities in shaft. The adjustable apparatus may be made of wood, iron, or other suitable material.

I make no claim to the invention of the conibination of a tube and shaft, for this, I am aware, is old.

What I claim as my invention is- The concave and convex peg or bolt D, in combination with the cavities in the shaft B and the hollow standard O, so as to produce an adjustable seat, chair, or stool, substantially as described.

BICKFORD N. HEMENWAY. XVitnesses:

JOHN GARR, PATRICK MGNAMARA. 

